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Siemens SINUMERIK Controller
Servo/Axis · Intermediate · 30-120 minutes
Siemens 300909 - Axis drive stop D triggered
This alarm indicates a STOP D (emergency stop) condition triggered by the drive system due to safety monitoring violations, hardware faults, or critical system errors. This is a safety-critical alarm requiring immediate attention and proper lockout/tagout procedures.
300909
Siemens 300909 - Axis drive stop D triggered
Axis drive stop D triggered
The drive ws stopped by the NC with STOP D. At the end of the stop reaction, the drive remains under control, the axis is monitored for SBH. Request: In monitoring cycle. If STOP D has been triggered, this can have several reasons (depending on the configuration): 1. The safe speed monitoring has been triggered (MD 1361: $MD_SAFE_VELO_STOP_MODE (SGspecific stop reaction) or MD 1363: $MD_SAFE_VELO_STOP_REACTION (SG-specific stop reaction) (840D as of SW4.2)). 2. The safe end-position monitoring has been triggered (MD 1362: $MD_SAFE_POS_STOP_MODE (safe end position stop reaction)). The alarm indicates the initiation of a "deceleration on path" in the NC and the internal activation of "safe standstill" in the NC and drive Control reaction: NC Start disable in this channel. Interface signals are set. Alarm display. NC Stop on alarm.
Root Cause Summary
This alarm indicates a STOP D (emergency stop) condition triggered by the drive system due to safety monitoring violations, hardware faults, or critical system errors. This is a safety-critical alarm requiring immediate attention and proper lockout/tagout procedures.
Safety
- Drive/power/encoder circuit: hazardous voltages may remain in the DC link after power-off. Lock out / tag out, wait for discharge per the drive documentation, and use qualified personnel only.
Causes and Fixes
- 1
SAFETY FIRST - Implement LOTO
Apply lockout/tagout procedures before any inspection. Ensure machine is in safe state.
- 2
Check drive diagnostics
Review drive-specific fault codes and status indicators for hardware issues.
- 3
Inspect safety circuits
Verify safety relay states, emergency stops, and protective door switches are functioning.
- 4
Check encoder and motor
Inspect encoder connections and motor temperature sensors for faults.
Call a technician if:
- ·Always for STOP D alarms - safety-critical condition
- ·If hardware faults are suspected
- ·If safety system configuration is involved
- ·If alarm persists after basic program checks
Prevention
- Regular safety system testing and validation
- Proper program validation before production runs
- Routine inspection of safety circuits and sensors
- Maintain updated machine documentation and safety parameters
Common Mistakes
- Overlooking safe speed limits in program
- Assuming all safety options are enabled by default
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